Starting Jan. 1, all apartments in Mecklenburg County must have carbon monoxide alarms.

The new rule is part of the county's strengthened carbon monoxide alarm ordinance, which now requires CO alarms in all dwellings in the county. The changes took effect Jan. 1, 2004, for homeowners.

According to officials, the revised law has already helped increase awareness and decrease poisoning cases.

"It's one of the most cost-effective programs we've implemented that has a direct impact on life safety," said Garry McCormick, hazardous materials coordinator for Charlotte-Mecklenburg Emergency Management.

Carbon monoxide is a colorless, odorless gas -- and the leading cause of poisoning deaths in the United States. Indeed, Mecklenburg County's original alarm ordinance was prompted by a 1999 incident at an uptown apartment complex that killed four.

Because CO is produced by burning fossil fuels, the original rule only required alarms in dwellings with attached garages or fuel-burning appliances.

But the December 2002 ice storm triggered a wave of CO poisoning that exposed that law's weaknesses. As a result, the board of county commissioners unanimously approved a beefed-up ordinance in 2003.

"It's definitely sparked public interest," notes Gerald Simpson of Faulk Brothers Hardware. "Prior to two years ago, we never sold (CO alarms)."

In 2000, before the first ordinance took effect, the Charlotte Fire Department received 253 CO-related calls. Two years later, the number jumped to 821. Today the figure is even higher, and the department has changed its record-keeping system to record it in detail. From June 2003 until Nov. 22, the department had received 945 calls for malfunctioning or misread CO alarms and 232 calls for bona fide CO incidents.

The number of false alarms is high, but McCormick says that demonstrates the program is working and residents have become more cognizant of the danger of carbon monoxide -- as was the case when smoke alarms first came on the market in the 1970s.

More than 100 other municipalities across the country, including New York and Chicago, have CO alarm requirements. But Mecklenburg County's comprehensive ordinance is one of the strongest in the country, health and fire officials say -- and one of the few in the South.

Nationwide, cost is the main obstacle to more widespread CO alarm legislation. Though the devices have become more affordable in recent years -- they typically cost $25 to $50 and are available at most hardware and home improvement stores -- the issue remains a concern to those in Charlotte who now support mandatory alarms.

"We as an organization have embraced the ordinance, but there is a cost burden to it," notes Ken Szymanskiconfirmed, executive director of the Charlotte Apartment Association.

More than 80,000 apartments have been affected by the law, and Szymanski said that CAA members have already spent well over $1 million on new alarms.

Bobby Cobb, a Mecklenburg County environmental health administrator, estimates that more than 50 percent of county households are currently complying with the law, with the number far higher among rental properties.

Though the penalty for noncompliance is $50, no citations have been issued yet. Instead, the county is focusing on education.

"Nobody's immune (from CO)," says Cobb. "Every income bracket, every age of home or rental unit -- we've seen practically every variation."

Authorities are also trying to reach out to Mecklenburg County's sizable international population, which the ice storm disproportionately affected.

"If they cooperate with (existing cultural) organizations, the chances of reaching the immigrant community are so much greater," recommends Angeles Ortega-Moore, executive director of the Latin American Coalition.

Even before it has fully taken effect, however, the ordinance has proven to be a rare thing -- something everybody in the community has come to agree and cooperate on. "It's the smart thing to do and the right thing to do," says Mecklenburg Health Director E. Winters Mabry.

Gayle Carelock, for one, is a believer. Her carbon monoxide alarm started the morning of Nov. 5 as an annoyance. By the afternoon, it had become a lifesaver.

After changing the batteries and resetting it that morning, Carelock learned the alarm had been unrelenting for a reason: Her aging furnace was leaking carbon monoxide.

The mother of two has learned her lesson. "When your alarm goes off, you pay attention," she says. "I think it's the greatest thing in the world to have."